Preparation Of Cerasus Humilis Kernel Peptide And Biological Activity Investigation

Kernel meal of Cerasus Humilis is a very important by-product of Cerasus Humilis processing, which rich of protein and unsaturated fatty acid. The Cerasus Humilis kernel meal contains about75%protein, and can be effectively utilized by enzymolysis. It becomes into small molecular peptide through hydrolysis, and will be more helpful to human digestion and absorption. It will provide enough nutrition to human being, at the same time its functional characteristics can be improved greatly. Cerasus Humilis kernel polypeptide (CHKP) also has good oxidation resistance and antibacterial activity. This test adopt single protease enzymolysis (CHKPs) and multiple enzymolysis (CHKPm) include alkaline protease, neutral protease, acid protease and trypsin to obtain polypeptide. And the bacteriostatic and in vitro antioxidant activities of the peptide were investigated, and the molecular weight of the peptides was determined. The follow is results:1.Preparation of CHKP:The optimal condition of single enzyme hydrolysis is:add1.5%(based on the substrate) alkaline protease into3%substrate solution, keep20minutes at pH10.2. CHKP in vitro antioxidant experiment:CHKPs and CHKPm both have markedly abilities to scavenging DPPH free radical, the IC50is0.94mg/ml and0.803mg/ml respectively; CHKP also has certain ability to move hydroxyl, the IC50value is2.52mg/ml and1.905mg/ml respectively; CHKP also could eliminate the super anion free radicals, the IC50values were1.44mg/ml and1.504mg/ml respectively; High concentrations of the CHKP showed excellent reducing power.3. Bacteriostatic experiment in vitro about CHKP:Bacteriostatic experiment results about CHKPm in vitro showed that compound enzyme hydrolysis of CHKP had better bacteriostasis than single one. When the concentration of sample is10mg/ml, bacteriostatic rates of strains as follow:staphylococcus aureus=60.73%, escherichia coli=53.25%, Shigella Castellani= 45.45%,listeria monocytogene=52.65%, salmonella typhi=47.06%, Manhattan salmonella=41.62%. The abilities to restrain bacteria:staphylococcus aureus> escherichia coli>listeria>salmonella typhi>Shigella Castellani> Manhattan salmonella.4. The molecular weight measure of CHKP:Through the analysis of concentration of8mg/ml’s CHKPs,it presents four different bands. According to its relative migration rate, the molecular weight is mainly around46.5,38.0,18.6,11.7KDa. It can illustrate the primary components of CHKPs are below50KDa. As for CHKPm, the results showed that the main ingredients of the molecular weight are mainly concentrated at850Da.